Propeller



July 21, 1931. I KS 1,815,192

I PROPELLER Filed Aug. 23, 1929 5 Sheets-Sheet l l l I l l Fay- mvENTOR July 21, 1931. T. A. DICKS 1,815,192

PROPELLER Filed Aug. 23. 1929 5 Sheets-Sheet 2 PROPELLER Filed Aug. 23, 1929 3 Sheets-Sheet 3 INVENTOR Maww Patented July 21, 1931 THOMAS A. DIOKS, OF PITTSBURGH,

AN'D BOLT CORPORATION, OF PENNSYLVANIA PATE NT, OFFICE PENNSYLVANIA, ASSIGN'OR TO PITTSBURGH SCREW PITTSBURGH, PENNSYLVANIA, A CORPORATION OF PROPELLER Application filed August 23, 1929. Serial No. 387,900.

The present application is a continuation in part of my copending application, Serial No. 387,899, filed August 23, 1929, for propeller for air craft.

This invention relates in general to air craft propellers in which the blades are detachably and adjustably secured in a hub construction.

Numerous attempts have been made to I produce a construction of this general type ments,

- the blades,

its operation, vibration and etc., all of which by using interlocking shoulders and abutor in someinstances by providing a threaded connection between the adjacent ends of the propeller blade and the hub, but in all of such cases, extreme care and expert workmanship must be exercised to provide a proper fit between the several parts. This necessarily entails high expense and adds materially to the ultimate cost of the propeller. It has also been found that propeller blades using such types of connections are diflicult to set to the proper pitch which is absolutely necessary to avoid uneven pull of wobbling of the propeller during tend to rob the air craft of its highest motive force. Then again the interlocking shoulders and abutments .or the threaded connections have been found to so tightly bind or set, due to the extremely high centrifugal action of the blades, that it is with difficulty that the blades may be detached when such is desired.

The principal object of the present invention resides in the novel manner of providing a detachable connection between the hub and the blade of the propeller which obviates all complex locking connections between the propeller blade and the hub.

Another object of the invention is the prosides in the yieldability of the wall of the socket arranged on the hub section so as to enable a clamping or gripping effect to' be had when the cross bolt or pin is properly tightened or secured.

With these and other objects in view, as will readily present themselves to those skilled in this art, I will now proceed with the detailed description of the invention. In the accompanying drawings wherein similar letters of reference indicate like parts throughout the several views; 7 a

Fig. 1 is a longitudinal cross section showing the type of connection utilized in the present instance;

- Fig. 2 is a longitudinal medial section of Fig. 1; and

Fig. 3 is anend view.v

In the drawings attached hereto, I have shown a ropeller construction provided with two dlametrically opposite blades, but

it will of course be understood that this number maybe increased to any desired extent so long as the individual construction of the hub socket 2 and the type of connection is employed.

Referring more-in detail to the drawings, 5 designates a hub provided with a transverse axial sleeve 6 into which a drive shaft is adapted to be secured in any appropriate or well-known manner. Integrally formed on the hub section 5 "are socket members 7. Each of the sockets is provided with a relatively thickened portion adjacent its point of connection to the hub 5 as designated by the reference character 8 and a relatively reduced portion 9 which extends to the outer end of the socket. The socket 7 is longitudinally slit at its outer end as at 10 and provided with outwardly extending ears 11. The ears 11 are suitably apertured for the reception of a bolt 12. The thickened portion 8 of the socket 7 is longitudinally cut or slit as shown at 13'for a purpose which will be hereinafter described.

The propeller blade shown in the present instance. is of tubular constructionand its inner end is adapted to be inserted within the socket 7 on the hub portion 5. Adjacent the inner end the propeller blades are suit-' .ter 17 apertured as designated by the characto permit the passage of the cross bolt 16.

It will be observed that the wall of the tubular propeller blade is relatively thin and I therefore prefer to strengthen the same at the points where it is apertured. This I ably may accomplish by the use of metallic blocks or inserts 18. In the present construction these metallic blocks or inserts are welded to the interior surface of the propeller blade wall and such welded joints are indicated by the reference numeral 14. The blocks or inserts are apertured at 15 as shown for the passage therethrough of bolt 16. As is further clear from the drawings, the blocks or inserts are welded at both upper and lower edges, the bottom weld being substantially flush with the lower edge of the tubular propeller blade. An unusually and unexpected- 1y strong and eflicient reinforcement is thus secured.

In the present case, I have shown the cross bolt or pin of angular formation, but it is, of course, understood that other types of cross keys may be employed if desired. One end of this cross key 16 is provlded with anarcuate head 21 which is adapted to fit snugly against the outer peripheral wall of the socket portion 7. The opposite end of the cross bolt is threaded'as at 22 for 'the reception of a nut 23. The cross bolt as well as the nut may be rovided with apertures for the reception 0 a cotter pin or any other suitable type of fastening to firmly retain the nut in its tightly adj usted thickened portion'8 of socket may be suitably countersunk as at 19 for the reception of the arcuate head 21 and nut 23, respec tively. This makes the assembly still firmer and stronger enablin it to resist stresses and strains even more e ectively.

A key-way 4 is provided in tapering bore 6 of the hub 5, the purpose of whichis well known. Apertures 15 and 17, as shown, are a little larger than bolt 16 so as to provide the necessary or required space for adjustment to exact position.

Upon insertion of the tubular end of the propeller blade, the various apertures are brought into registration and the cross bolt inserted therethrough. The individual propeller blades are then properly adjusted in regards to angle or pitch and are then tightly held in clam ed position through the action of the cross ey 16 and its associated nut 23. The cross bolt 12, positioned in the outer end of the socket, closes the latter so that it grips the tubular blade, and further reinforces the positioning of this blade. This latter action will tightly draw the inner portion of the socket around the inner end of the inserted tubular blade and during this action the walls of the thickened portion will yield slightly owing to the longitudinal slit 13.

position. The

When it is desired to replace any of the blades in case of damage, all that is necessary is to release and withdraw the cross pin and secondly, to loosen the cross bolt 12 in its bind or grip of the outer end of the socket upon the inserted blade. With the release of said parts the blade may be easily removed by simply withdrawing the same from its socket.

While I have described in the foregoing, the preferred form of my invention, I wish it understood that certain departures therefrom may be resorted to so long as the structure falls within the terms of the appended claims.

I claim 1. In a propeller, a hub having a series of sockets radiating therefrom, the inner wall portion of each socket being relatively thick, a detachable tubular blade having a relatively thin walled shank adapted to fit within each socket, the thickened portion of the socket and the blade being provided with suitable openings for the reception of a cross bolt, and metal inserts secured to the inner wall of the inserted shank to reinforce the same at the point where the cross bolt passes therethrough.

2. In a propeller, a hub having a series of sockets radiating therefrom, the inner wall ortion being relatively thick, a detachable tubular blade having a relatively thin walled shank adapted to fit'within each socket, the

socket and the shank of the blade being provided with suitable openings for the reception of a cross bolt and means for reinforcing the walls of the shank at the point where the cross bolt passes therethrough, said reinforcing means=comprising metal inserts welded to the inner wall of the shank.

3. In a propeller, a hub having a series of sockets radiating therefrom, each provided with inner and outer wall portions the inner wall portion of each socket being re atively thicker than the outer wall portion, a detachable tubular blade having a relatively thin walled hollow shank adapted to fit within each socket, the thickened inner portion of the socket and the shank being provided with suitable openings for the reception of a cross bolt, and metal inserts secured to the inner wall of the shank to reinforce the same at the point where the cross bolt passes therethrough, said reinforcing metal inserts being welded to said wall.

4. In a propeller, a hub having a series of sockets radiating therefrom, each socket having an inner wall portion and an outer wall portion the inner wall portion of each socket being relatively thicker than the outer wall portion, a detachable tubular blade having a relatively thin solid walled shank adapted to fit within each socket, the thickened inner portion of the socket and the shank being provided with suitable openings for the reception of ,a cross bolt, and metal inserts secured to the inner wall of the shank to reinforce the same at the point where the cross bolt passes therethrou h, said reinforcing metal 5 inserts being welfed top and bottom to said wall and provided with openings registering with the openings in the socket and shank of said blade.

5. In a propeller, a hub having a series ofsockets extending radially therefrom, a detachable tubular blade adapted to be received in each of said sockets, metallic reinforcing members on the inner wall of said blade, a cross-bolt extending through registering openings in said socket and blade and means for clamping said socket around said blade, said means comprising a longitudinally extending split in the outer portion of said socket provided with clamping lugs on op- 2 posite sides thereof and radial slits on the inner portion of said socket for permitting yieldability under clamping action.

6. In a propeller, a hub having a series of sockets extending radially therefrom, each. socket having an inner and outer portion, the inner portion being relatively thicker than the outer portion, a detachable tubular blade having a relatively thin walled shank adapted to fit within each of said sockets, a crossbolt extending .through registering openings in said socket and shank for securing the J blade to the hub, metallic inserts secured to the inner wall of said shank for reinforcing the same at the point where the cross-bolt passes therethrough, and means on the inner and outer portions of said sockets for permittin the same to be securely clamped around said shank.

7. In a propeller, a hub having a series of 40 said sockets radiating therefrom, each of said sockets having an inner and outer portion, the inner portion being relatively thicker than the outer portion, a detachable tubular blade having a relatively thin walled shank 4 adapted to fit within each of said sockets, metallic inserts secured to the inner wall of said shank, a cross-bolt extending through apertures in the inner portion of said socket, the shank, and the inserts for securing the 30 blade to the hub, and means for clamping said socket around said shank, said means comprising a longitudinally extending split in said outer portion, a clamping'means on opposite sides of said split and slits in the inner portion of said socket for permitting yieldability thereof under clamping action.

In testimony whereof, I have hereunto subscribed my name this 21st day of August, 1929. so THOMAS A. DIGKS 

